Identification of a simple screening tool for dysphagia in patients with stroke using factor analysis of multiple dysphagia variables.

OBJECTIVE To identify a most useful and simple clinical screening tool to predict videofluoroscopic aspiration in patients with stroke. DESIGN Factor analysis of multiple dysphagia variables and sensitivity and specificity testing with chi-square test. PATIENTS Sixty-one consecutive stroke patients with symptoms suggestive of dysphagia admitted to a university hospital and its 4 affiliated hospitals in Japan. METHODS Factors were extracted from 6 oromotor examinations (lip closure, tongue movement, palatal elevation, gag reflex, voice quality and motor speech function), 2 swallow screen tests (saliva swallowing test and our modified water swallowing test using 30 ml of water) and 4 parameters evaluated with a videofluoroscopic swallow study. Sensitivity and specificity of each dysphagia-related variable was determined against aspiration in a videofluoroscopic swallow study. RESULTS Factor analysis revealed that cough/voice change in the water swallowing test and aspiration on videofluoroscopic swallow study belonged to the same factor. Chi-square analysis showed that cough/voice change in the water swallowing test was the only variable that was significantly associated with aspiration on videofluoroscopic swallow study, with a sensitivity of 72% (95% CI: 61-83%) and a specificity of 67% (CI: 55-79%) as a predictor of aspiration (p<0.05). CONCLUSION We recommend our modified 30 ml water-swallowing test as a useful single task-screening tool to detect aspiration.